Return-to-zero device for calculating-machines.



'W. AUGUSTIN. RETURN-T042380 DEVICE FOR CALCULATING MACHINES. I

Arrmoulol nun nn. 2, ma.

1,086,34A. rimmed Feb.10,1914.

llllh Ill I |llIIllll I Illllllll--!!I Imam" m WILHELM AUGUSTIN, 0F CHARLOTTENBURG, GERMANY.

RETURN-'lO-ZERO DEVICE FOR CALCULATING-MACHINES.

Specification of Letters Patent.

Application filed April 2, 1913. Serial No. 758,317.

To all whom itmay concern Be it known that I, WVILHE M Aneusrix, a citizen of the Empire of Germany, residing at"Charlotte nburg, in the Empire of Germany, have invented a new and useful Return-to-Zero Device for Calculating-Niachines, of which the following is a specification.

My invention relates to calculating machines and especially to improvements in the mechanism of such machines connected with the result indicators, whereby such mechanism is, when required, brought back to the zero position.

Under the present invention the setting or starting levers of calculating machines are brought back to the zero position by means of a suitably shaped disk'fitted on the reg:

' ,istering shaft of the result mechanism. The

disk. actuates an intermediate gear which, in turn, puts pawl mechanism out of gear so that the result spindle can be easily and conv'eniently brought back to the'zero position by mea-ns'of a thumb screw or the like.

It is a well known'fact that. with calculating machines, such for instance as disclosed in British Patent No. 281465 of 1910, the

- several result indicating wheels and cooperating parts aretemporarily maintained in the posit-ion to which they have been set, by brakes or other retaining elements that are influenced by comparatively strong springs. It is therefore obvious that whenever ,the result indicators, etc, are returned to their zero position, the retaining. members not only greatly impede such operation, thus necessitating the expenditure of a large Y amount of manual labor, but they also cause -a quick wearingout of the parts.

-Upon the calculating shaft Y, carrying winged nut Z are mounted the toothed calculating wheels V, which may be rotated independent of said shaft,'one of such wheels only being shown in the drawing. \Vheel \V is adapted to be engaged by a retaining pawl J fulcrumed at. X and provided with a heel J extending beyond said fulcrum. Upon shaft Y is further firmly mounted a cam disk X having a flattened section to. said cam disk being engaged by a lever X fuleruined at X The rear arm of lever X carries a stud or abutment X that engages the lower side of heel J For returning the wheel. V to its Zero position, nut Z is rotated so as to cause shaft Y to be moved in an aXial direction until it becomes coupled to .the wheel (said well known coupling etc. mechanism being not shown as not forming part of the present invention). As cam X participates in this rotation of shaft Y, said cam will swing the forward end of lever X downward, so that. stud X is raised to tilt pawl J out of engagement with wheel W.

ing, wheel is thus freely returned to its zero position. After the rotation of shaft Y has been completed, disk X will occupy its original position, so that lever X engages the flatteneddisk section 02 and stud X is lowered to permit a ree'ngagement be tween the pawl J and' wheel V.

I claim:

A return-to-Zero device for calculating machines comprising a rotatable shaft, a cam disk fast thereon, a lever having a heel and engaging said disk, a toothed wheel carried by the shaft, a pawl adapted to engage said wheel, and an abutment on the pawl that engages the lever-heel.

WVILI-IELM AUGU STIN.

Witnesses HENRY HASPER, VOLDEM AR HAUPT.

Patented Feb. 10, 1914.

During the 0011- I tinned rotation of theshaft Y, the calculat- 

